The present invention generally relates to a milling cutter for chip removing machining, a milling cutter body and an indexable cutting insert that is intended to be mounted to a milling cutter body.
A milling cutter is previously known, which comprises a milling cutter body that is provided with a number of indexable cutting inserts. Each indexable cutting insert comprises a number of main cutting edges and a minor cutting edge associated with each major cutting edge. A minor cutting edge forms a right angle with an associated major cutting edge. This known milling cutter is especially intended for milling of right-angled corners in a work piece. A drawback that this known milling cutter has is that the cutting depth is limited to the length of the main cutting edge since the minor cutting edge on same edge as the cutting insert is situated radially outside of the main cutting edge when the cutting insert is mounted on the milling cutter body.
A face milling cutter is also known which comprises first cutting inserts the center holes of which are essentially axially directed and second cutting inserts the center holes of which are essentially radially directed relative to a holder of the face milling cutter. The first and second cutting inserts are identical. According to a preferred embodiment each cutting insert comprises four cutting insert corners, however different parts of the cutting inserts are used as active cutting edges depending on whether the center holes are oriented axially or radially. In relation to the present invention the cutting inserts with axially directed center hole are most pertinent. In order to activate all four cutting insert corners in one position with axially directed center holes the cutting inserts must be both indexed and flipped.
It is desirable to provide a milling cutter and indexable cutting inserts adapted thereto, the milling cutter being able to machine right-angled corners in a work piece to great cutting depths.
It is also desirable to provide the indexable cutting inserts according to an aspect of the present invention provided in the milling cutter according to the present invention must be indexable four times during its life-span.
It is also desirable to orient indexable cutting inserts such that they can be secured by means of center screws with a relatively long length of anchor.
According to an aspect of the present invention, a milling cutter for chip removing machining comprises a milling cutter body with a plurality of cutting insert seats proximate an end of the milling cutter body, the milling cutter body being adapted to cooperate with a tool attachment at an opposite end of the milling cutter body in an axial direction, indexable cutting inserts being secured in the cutting insert seats, each indexable cutting insert having a top surface and a bottom surface substantially parallel with the top surface, wherein side surfaces extend between the top surface and the bottom surface, wherein each indexable cutting insert has a basic shape of a truncated pyramid, and each indexable cutting insert has a top surface facing towards a chip removing end of the milling cutter, and main cutting edges of the indexable cutting insert extend from the top surface of the indexable cutting insert in a direction towards the bottom surface of the indexable cutting insert.
According to another aspect of the present invention, a milling cutter body comprises a free end with a plurality of cutting insert seats proximate the free end, the milling cutter body being adapted to cooperate with a tool attachment at an opposite end in the axial direction, each cutting insert seat comprising a plurality of support surfaces, wherein a support surface that is facing towards the free end of the milling cutter body has means for cooperating with a clamping means for an indexable cutting insert having the basic shape of a truncated pyramid.
According to another aspect of the present invention, an indexable cutting insert that is intended to be mounted in a cutting insert seat of a milling cutter body comprises a top surface and a bottom surface substantially parallel with the top surface, wherein side surfaces connect the top surface and the bottom surface, wherein the indexable cutting insert has the basic shape of a truncated pyramid and main cutting edges of the indexable cutting insert extend from the top surface in direction towards the bottom surface.